ever built. yes. a $400 billion price tag as the pentagon faces $500 billion spending cuts. what's going on? stand by. >>> i'm dr. sanjay gupta. meet ed lew. he's building a space tell low scope. he says it's going to protect the earth from asteroids. >> this is the space telescope. >> that's it? that's the size of it there? >> yeah. the real one is about the size of, say, a delivery truck. so it's about 23, 24 feet tall. and it's about 3,000 pounds. over a 6 1/2-year period, it's going to scan earth's orbit multiple times and those are the asteroids it could get hit with. >> so it's going to track about 10,000 asteroids. >> each month? >> each month. yes. which is more than all other telescopes throughout history. it will do that every month. >> watch more on the urgent mission to save planet earth this sunday on "the next list." [ male announcer ] any technology not moving forward is moving backward. [ engine turns over, tires squeal ] and you'll find advanced safety technology like an available heads-up display on the 2013 lexus gs. there's no going back. on the 2013 lexus gs.